X-Git-Url: https://git.sesse.net/?p=stockfish;a=blobdiff_plain;f=src%2Fsearch.cpp;h=d47fab1fea3564f3c944717b9c26295f2d9653bb;hp=fab117808532347af74a6569f5b14e02cf7b69ee;hb=876ceb1feb466f4dd2e29d01433878b8cf29cd6f;hpb=846087e4fb0bd2c330df67b63245f7ead44d8c36 diff --git a/src/search.cpp b/src/search.cpp index fab11780..d47fab1f 100644 --- a/src/search.cpp +++ b/src/search.cpp @@ -129,7 +129,7 @@ namespace { void extract_pv_from_tt(Position& pos); void insert_pv_in_tt(Position& pos); - std::string pv_info_to_uci(Position& pos, Depth depth, Value alpha, Value beta, int pvLine = 0); + std::string pv_info_to_uci(Position& pos, int depth, Value alpha, Value beta, int pvLine = 0); int64_t nodes; Value pv_score; @@ -145,9 +145,7 @@ namespace { typedef std::vector Base; - RootMoveList(Position& pos, Move searchMoves[]); - void set_non_pv_scores(const Position& pos, Move ttm, SearchStack* ss); - + void init(Position& pos, Move searchMoves[]); void sort() { insertion_sort(begin(), end()); } void sort_multipv(int n) { insertion_sort(begin(), begin() + n); } @@ -205,8 +203,8 @@ namespace { // Extensions. Configurable UCI options // Array index 0 is used at non-PV nodes, index 1 at PV nodes. - Depth CheckExtension[2], SingleEvasionExtension[2], PawnPushTo7thExtension[2]; - Depth PassedPawnExtension[2], PawnEndgameExtension[2], MateThreatExtension[2]; + Depth CheckExtension[2], PawnPushTo7thExtension[2], PassedPawnExtension[2]; + Depth PawnEndgameExtension[2], MateThreatExtension[2]; // Minimum depth for use of singular extension const Depth SingularExtensionDepth[2] = { 8 * ONE_PLY /* non-PV */, 6 * ONE_PLY /* PV */}; @@ -235,11 +233,6 @@ namespace { template inline Depth reduction(Depth d, int mn) { return (Depth) ReductionMatrix[PV][Min(d / 2, 63)][Min(mn, 63)]; } - // Common adjustments - - // Search depth at iteration 1 - const Depth InitialDepth = ONE_PLY; - // Easy move margin. An easy move candidate must be at least this much // better than the second best move. const Value EasyMoveMargin = Value(0x200); @@ -250,8 +243,8 @@ namespace { // Book object Book OpeningBook; - // Pointer to root move list - RootMoveList* Rml; + // Root move list + RootMoveList Rml; // MultiPV mode int MultiPV; @@ -296,7 +289,7 @@ namespace { } template - Depth extension(const Position& pos, Move m, bool captureOrPromotion, bool moveIsCheck, bool singleEvasion, bool mateThreat, bool* dangerous); + Depth extension(const Position& pos, Move m, bool captureOrPromotion, bool moveIsCheck, bool mateThreat, bool* dangerous); bool check_is_dangerous(Position &pos, Move move, Value futilityBase, Value beta, Value *bValue); bool connected_moves(const Position& pos, Move m1, Move m2); @@ -309,13 +302,13 @@ namespace { void update_history(const Position& pos, Move move, Depth depth, Move movesSearched[], int moveCount); void update_killers(Move m, Move killers[]); void update_gains(const Position& pos, Move move, Value before, Value after); + void qsearch_scoring(Position& pos, MoveStack* mlist, MoveStack* last); int current_search_time(); std::string value_to_uci(Value v); int nps(const Position& pos); void poll(const Position& pos); void wait_for_stop_or_ponderhit(); - void init_ss_array(SearchStack* ss, int size); #if !defined(_MSC_VER) void* init_thread(void* threadID); @@ -324,50 +317,69 @@ namespace { #endif - // A dispatcher to choose among different move sources according to the type of node + // MovePickerExt is an extended MovePicker used to choose at compile time + // the proper move source according to the type of node. template struct MovePickerExt; - // In Root nodes use RootMoveList Rml as source - template<> struct MovePickerExt { + // In Root nodes use RootMoveList Rml as source. Score and sort the root moves + // before to search them. + template<> struct MovePickerExt : public MovePicker { - MovePickerExt(const Position&, Move, Depth, const History&, SearchStack*, Value) - : rm(Rml->begin()), firstCall(true) {} + MovePickerExt(const Position& p, Move ttm, Depth d, const History& h, SearchStack* ss, Value b) + : MovePicker(p, ttm, d, h, ss, b), firstCall(true) { + Move move; + Value score = VALUE_ZERO; - Move get_next_move() { + // Score root moves using the standard way used in main search, the moves + // are scored according to the order in which are returned by MovePicker. + // This is the second order score that is used to compare the moves when + // the first order pv scores of both moves are equal. + while ((move = MovePicker::get_next_move()) != MOVE_NONE) + for (rm = Rml.begin(); rm != Rml.end(); ++rm) + if (rm->pv[0] == move) + { + rm->non_pv_score = score--; + break; + } - if (!firstCall) - ++rm; - else - firstCall = false; + Rml.sort(); + rm = Rml.begin(); + } - return rm != Rml->end() ? rm->pv[0] : MOVE_NONE; - } - int number_of_evasions() const { return (int)Rml->size(); } + Move get_next_move() { + + if (!firstCall) + ++rm; + else + firstCall = false; - RootMoveList::iterator rm; - bool firstCall; + return rm != Rml.end() ? rm->pv[0] : MOVE_NONE; + } + + RootMoveList::iterator rm; + bool firstCall; }; - // In SpNodes use split point's shared MovePicker as move source - template<> struct MovePickerExt { + // In SpNodes use split point's shared MovePicker object as move source + template<> struct MovePickerExt : public MovePicker { - MovePickerExt(const Position&, Move, Depth, const History&, SearchStack* ss, Value) - : mp(ss->sp->mp) {} + MovePickerExt(const Position& p, Move ttm, Depth d, const History& h, + SearchStack* ss, Value b) : MovePicker(p, ttm, d, h, ss, b), + mp(ss->sp->mp) {} - Move get_next_move() { return mp->get_next_move(); } - int number_of_evasions() const { return mp->number_of_evasions(); } + Move get_next_move() { return mp->get_next_move(); } - RootMoveList::iterator rm; // Dummy, never used - MovePicker* mp; + RootMoveList::iterator rm; // Dummy, needed to compile + MovePicker* mp; }; - // Normal case, create and use a MovePicker object as source + // Default case, create and use a MovePicker object as source template<> struct MovePickerExt : public MovePicker { - MovePickerExt(const Position& p, Move ttm, Depth d, const History& h, - SearchStack* ss, Value beta) : MovePicker(p, ttm, d, h, ss, beta) {} + MovePickerExt(const Position& p, Move ttm, Depth d, const History& h, + SearchStack* ss, Value b) : MovePicker(p, ttm, d, h, ss, b) {} - RootMoveList::iterator rm; // Dummy, never used + RootMoveList::iterator rm; // Dummy, needed to compile }; } // namespace @@ -488,8 +500,6 @@ bool think(Position& pos, bool infinite, bool ponder, int time[], int increment[ CheckExtension[1] = Options["Check Extension (PV nodes)"].value(); CheckExtension[0] = Options["Check Extension (non-PV nodes)"].value(); - SingleEvasionExtension[1] = Options["Single Evasion Extension (PV nodes)"].value(); - SingleEvasionExtension[0] = Options["Single Evasion Extension (non-PV nodes)"].value(); PawnPushTo7thExtension[1] = Options["Pawn Push to 7th Extension (PV nodes)"].value(); PawnPushTo7thExtension[0] = Options["Pawn Push to 7th Extension (non-PV nodes)"].value(); PassedPawnExtension[1] = Options["Passed Pawn Extension (PV nodes)"].value(); @@ -586,110 +596,91 @@ bool think(Position& pos, bool infinite, bool ponder, int time[], int increment[ namespace { - // id_loop() is the main iterative deepening loop. It calls search() - // repeatedly with increasing depth until the allocated thinking time has - // been consumed, the user stops the search, or the maximum search depth is - // reached. + // id_loop() is the main iterative deepening loop. It calls search() repeatedly + // with increasing depth until the allocated thinking time has been consumed, + // user stops the search, or the maximum search depth is reached. Move id_loop(Position& pos, Move searchMoves[], Move* ponderMove) { SearchStack ss[PLY_MAX_PLUS_2]; - - Depth depth; - Move EasyMove = MOVE_NONE; - Value value, alpha = -VALUE_INFINITE, beta = VALUE_INFINITE; - int researchCountFL, researchCountFH; - - int iteration; + Value bestValues[PLY_MAX_PLUS_2]; int bestMoveChanges[PLY_MAX_PLUS_2]; - Value values[PLY_MAX_PLUS_2]; - int aspirationDelta = 0; + int depth, researchCountFL, researchCountFH, aspirationDelta; + Value value, alpha, beta; + Move bestMove, easyMove; // Moves to search are verified, scored and sorted - RootMoveList rml(pos, searchMoves); - Rml = &rml; + Rml.init(pos, searchMoves); + + // Initialize FIXME move before Rml.init() + TT.new_search(); + H.clear(); + memset(ss, 0, PLY_MAX_PLUS_2 * sizeof(SearchStack)); + *ponderMove = bestMove = easyMove = MOVE_NONE; + depth = aspirationDelta = 0; + ss->currentMove = MOVE_NULL; // Hack to skip update_gains() + alpha = -VALUE_INFINITE, beta = VALUE_INFINITE; // Handle special case of searching on a mate/stale position - if (rml.size() == 0) + if (Rml.size() == 0) { - Value s = (pos.is_check() ? -VALUE_MATE : VALUE_DRAW); - - cout << "info depth " << 1 - << " score " << value_to_uci(s) << endl; + cout << "info depth 0 score " + << value_to_uci(pos.is_check() ? -VALUE_MATE : VALUE_DRAW) + << endl; return MOVE_NONE; } - // Initialize - TT.new_search(); - H.clear(); - init_ss_array(ss, PLY_MAX_PLUS_2); - values[1] = rml[0].pv_score; - iteration = 1; - - // Send initial RootMoveList scoring (iteration 1) - cout << set960(pos.is_chess960()) // Is enough to set once at the beginning - << "info depth " << iteration - << "\n" << rml[0].pv_info_to_uci(pos, ONE_PLY, alpha, beta) << endl; - // Is one move significantly better than others after initial scoring ? - if ( rml.size() == 1 - || rml[0].pv_score > rml[1].pv_score + EasyMoveMargin) - EasyMove = rml[0].pv[0]; + if ( Rml.size() == 1 + || Rml[0].pv_score > Rml[1].pv_score + EasyMoveMargin) + easyMove = Rml[0].pv[0]; // Iterative deepening loop - while (iteration < PLY_MAX) + while (++depth <= PLY_MAX && (!MaxDepth || depth <= MaxDepth) && !StopRequest) { - // Initialize iteration - iteration++; - Rml->bestMoveChanges = 0; - - cout << "info depth " << iteration << endl; + Rml.bestMoveChanges = researchCountFL = researchCountFH = 0; + cout << "info depth " << depth << endl; // Calculate dynamic aspiration window based on previous iterations - if (MultiPV == 1 && iteration >= 6 && abs(values[iteration - 1]) < VALUE_KNOWN_WIN) + if (MultiPV == 1 && depth >= 5 && abs(bestValues[depth - 1]) < VALUE_KNOWN_WIN) { - int prevDelta1 = values[iteration - 1] - values[iteration - 2]; - int prevDelta2 = values[iteration - 2] - values[iteration - 3]; + int prevDelta1 = bestValues[depth - 1] - bestValues[depth - 2]; + int prevDelta2 = bestValues[depth - 2] - bestValues[depth - 3]; - aspirationDelta = Max(abs(prevDelta1) + abs(prevDelta2) / 2, 16); + aspirationDelta = Min(Max(abs(prevDelta1) + abs(prevDelta2) / 2, 16), 24); aspirationDelta = (aspirationDelta + 7) / 8 * 8; // Round to match grainSize - alpha = Max(values[iteration - 1] - aspirationDelta, -VALUE_INFINITE); - beta = Min(values[iteration - 1] + aspirationDelta, VALUE_INFINITE); + alpha = Max(bestValues[depth - 1] - aspirationDelta, -VALUE_INFINITE); + beta = Min(bestValues[depth - 1] + aspirationDelta, VALUE_INFINITE); } - depth = (iteration - 2) * ONE_PLY + InitialDepth; - - researchCountFL = researchCountFH = 0; - - // We start with small aspiration window and in case of fail high/low, we - // research with bigger window until we are not failing high/low anymore. + // Start with a small aspiration window and, in case of fail high/low, + // research with bigger window until not failing high/low anymore. while (true) { - // Sort the moves before to (re)search - rml.set_non_pv_scores(pos, rml[0].pv[0], ss); - rml.sort(); - - // Search to the current depth - value = search(pos, ss, alpha, beta, depth, 0); - - // Sort the moves and write PV lines to transposition table, in case - // the relevant entries have been overwritten during the search. - rml.sort(); - for (int i = 0; i < Min(MultiPV, (int)rml.size()); i++) - rml[i].insert_pv_in_tt(pos); + // Search starting from ss+1 to allow calling update_gains() + value = search(pos, ss+1, alpha, beta, depth * ONE_PLY, 0); - bestMoveChanges[iteration] = Rml->bestMoveChanges; + // Send PV line to GUI and write to transposition table in case the + // relevant entries have been overwritten during the search. + for (int i = 0; i < Min(MultiPV, (int)Rml.size()); i++) + { + Rml[i].insert_pv_in_tt(pos); + cout << set960(pos.is_chess960()) + << Rml[i].pv_info_to_uci(pos, depth, alpha, beta, i) << endl; + } + // Value cannot be trusted. Break out immediately! if (StopRequest) break; assert(value >= alpha); + // In case of failing high/low increase aspiration window and research, + // otherwise exit the fail high/low loop. if (value >= beta) { - // Prepare for a research after a fail high, each time with a wider window beta = Min(beta + aspirationDelta * (1 << researchCountFH), VALUE_INFINITE); researchCountFH++; } @@ -698,7 +689,6 @@ namespace { AspirationFailLow = true; StopOnPonderhit = false; - // Prepare for a research after a fail low, each time with a wider window alpha = Max(alpha - aspirationDelta * (1 << researchCountFL), -VALUE_INFINITE); researchCountFL++; } @@ -706,44 +696,41 @@ namespace { break; } - if (StopRequest) - break; // Value cannot be trusted. Break out immediately! - - //Save info about search result - values[iteration] = value; + // Collect info about search result + bestMove = Rml[0].pv[0]; + bestValues[depth] = value; + bestMoveChanges[depth] = Rml.bestMoveChanges; // Drop the easy move if differs from the new best move - if (rml[0].pv[0] != EasyMove) - EasyMove = MOVE_NONE; + if (bestMove != easyMove) + easyMove = MOVE_NONE; - if (UseTimeManagement) + if (UseTimeManagement && !StopRequest) { // Time to stop? bool noMoreTime = false; - // Stop search early if there is only a single legal move, - // we search up to Iteration 6 anyway to get a proper score. - if (iteration >= 6 && rml.size() == 1) - noMoreTime = true; - // Stop search early when the last two iterations returned a mate score - if ( iteration >= 6 - && abs(values[iteration]) >= abs(VALUE_MATE) - 100 - && abs(values[iteration-1]) >= abs(VALUE_MATE) - 100) + if ( depth >= 5 + && abs(bestValues[depth]) >= abs(VALUE_MATE) - 100 + && abs(bestValues[depth - 1]) >= abs(VALUE_MATE) - 100) noMoreTime = true; - // Stop search early if one move seems to be much better than the others - if ( iteration >= 8 - && EasyMove == rml[0].pv[0] - && ( ( rml[0].nodes > (pos.nodes_searched() * 85) / 100 + // Stop search early if one move seems to be much better than the + // others or if there is only a single legal move. In this latter + // case we search up to Iteration 8 anyway to get a proper score. + if ( depth >= 7 + && easyMove == bestMove + && ( Rml.size() == 1 + ||( Rml[0].nodes > (pos.nodes_searched() * 85) / 100 && current_search_time() > TimeMgr.available_time() / 16) - ||( rml[0].nodes > (pos.nodes_searched() * 98) / 100 + ||( Rml[0].nodes > (pos.nodes_searched() * 98) / 100 && current_search_time() > TimeMgr.available_time() / 32))) noMoreTime = true; // Add some extra time if the best move has changed during the last two iterations - if (iteration > 5 && iteration <= 50) - TimeMgr.pv_instability(bestMoveChanges[iteration], bestMoveChanges[iteration-1]); + if (depth > 4 && depth < 50) + TimeMgr.pv_instability(bestMoveChanges[depth], bestMoveChanges[depth-1]); // Stop search if most of MaxSearchTime is consumed at the end of the // iteration. We probably don't have enough time to search the first @@ -759,13 +746,10 @@ namespace { break; } } - - if (MaxDepth && iteration >= MaxDepth) - break; } - *ponderMove = rml[0].pv[1]; - return rml[0].pv[0]; + *ponderMove = Rml[0].pv[1]; + return bestMove; } @@ -795,9 +779,9 @@ namespace { ValueType vt; Value bestValue, value, oldAlpha; Value refinedValue, nullValue, futilityBase, futilityValueScaled; // Non-PV specific - bool isPvMove, isCheck, singleEvasion, singularExtensionNode, moveIsCheck, captureOrPromotion, dangerous; + bool isPvMove, isCheck, singularExtensionNode, moveIsCheck, captureOrPromotion, dangerous; bool mateThreat = false; - int moveCount = 0; + int moveCount = 0, playedMoveCount = 0; int threadID = pos.thread(); SplitPoint* sp = NULL; @@ -814,36 +798,33 @@ namespace { mateThreat = sp->mateThreat; goto split_point_start; } - else {} // Hack to fix icc's "statement is unreachable" warning + else if (Root) + bestValue = alpha; // Step 1. Initialize node and poll. Polling can abort search ss->currentMove = ss->bestMove = threatMove = MOVE_NONE; (ss+2)->killers[0] = (ss+2)->killers[1] = (ss+2)->mateKiller = MOVE_NONE; - if (!Root) + if (threadID == 0 && ++NodesSincePoll > NodesBetweenPolls) { - if (threadID == 0 && ++NodesSincePoll > NodesBetweenPolls) - { - NodesSincePoll = 0; - poll(pos); - } - - // Step 2. Check for aborted search and immediate draw - if ( StopRequest - || ThreadsMgr.cutoff_at_splitpoint(threadID) - || pos.is_draw() - || ply >= PLY_MAX - 1) - return VALUE_DRAW; - - // Step 3. Mate distance pruning - alpha = Max(value_mated_in(ply), alpha); - beta = Min(value_mate_in(ply+1), beta); - if (alpha >= beta) - return alpha; + NodesSincePoll = 0; + poll(pos); } - // Step 4. Transposition table lookup + // Step 2. Check for aborted search and immediate draw + if (( StopRequest + || ThreadsMgr.cutoff_at_splitpoint(threadID) + || pos.is_draw() + || ply >= PLY_MAX - 1) && !Root) + return VALUE_DRAW; + // Step 3. Mate distance pruning + alpha = Max(value_mated_in(ply), alpha); + beta = Min(value_mate_in(ply+1), beta); + if (alpha >= beta) + return alpha; + + // Step 4. Transposition table lookup // We don't want the score of a partial search to overwrite a previous full search // TT value, so we use a different position key in case of an excluded move exists. excludedMove = ss->excludedMove; @@ -852,14 +833,13 @@ namespace { tte = TT.retrieve(posKey); ttMove = tte ? tte->move() : MOVE_NONE; - // At PV nodes, we don't use the TT for pruning, but only for move ordering. - // This is to avoid problems in the following areas: - // - // * Repetition draw detection - // * Fifty move rule detection - // * Searching for a mate - // * Printing of full PV line - if (!PvNode && tte && ok_to_use_TT(tte, depth, beta, ply)) + // At PV nodes we check for exact scores, while at non-PV nodes we check for + // and return a fail high/low. Biggest advantage at probing at PV nodes is + // to have a smooth experience in analysis mode. + if ( !Root + && tte + && (PvNode ? tte->depth() >= depth && tte->type() == VALUE_TYPE_EXACT + : ok_to_use_TT(tte, depth, beta, ply))) { TT.refresh(tte); ss->bestMove = ttMove; // Can be MOVE_NONE @@ -885,8 +865,7 @@ namespace { } // Save gain for the parent non-capture move - if (!Root) - update_gains(pos, (ss-1)->currentMove, (ss-1)->eval, ss->eval); + update_gains(pos, (ss-1)->currentMove, (ss-1)->eval, ss->eval); // Step 6. Razoring (is omitted in PV nodes) if ( !PvNode @@ -979,9 +958,8 @@ namespace { } // Step 9. Internal iterative deepening - if ( !Root - && depth >= IIDDepth[PvNode] - && ttMove == MOVE_NONE + if ( depth >= IIDDepth[PvNode] + && ttMove == MOVE_NONE && (PvNode || (!isCheck && ss->eval >= beta - IIDMargin))) { Depth d = (PvNode ? depth - 2 * ONE_PLY : depth / 2); @@ -995,7 +973,7 @@ namespace { } // Expensive mate threat detection (only for PV nodes) - if (PvNode && !Root) // FIXME + if (PvNode) mateThreat = pos.has_mate_threat(); split_point_start: // At split points actual search starts from here @@ -1004,7 +982,6 @@ split_point_start: // At split points actual search starts from here MovePickerExt mp(pos, ttMove, depth, H, ss, (PvNode ? -VALUE_INFINITE : beta)); CheckInfo ci(pos); ss->bestMove = MOVE_NONE; - singleEvasion = !SpNode && isCheck && mp.number_of_evasions() == 1; futilityBase = ss->eval + ss->evalMargin; singularExtensionNode = !Root && !SpNode @@ -1014,9 +991,6 @@ split_point_start: // At split points actual search starts from here && !excludedMove // Do not allow recursive singular extension search && (tte->type() & VALUE_TYPE_LOWER) && tte->depth() >= depth - 3 * ONE_PLY; - if (Root) - bestValue = alpha; - if (SpNode) { lock_grab(&(sp->lock)); @@ -1039,7 +1013,7 @@ split_point_start: // At split points actual search starts from here else if (move == excludedMove) continue; else - movesSearched[moveCount++] = move; + moveCount++; if (Root) { @@ -1069,7 +1043,7 @@ split_point_start: // At split points actual search starts from here captureOrPromotion = pos.move_is_capture_or_promotion(move); // Step 11. Decide the new search depth - ext = extension(pos, move, captureOrPromotion, moveIsCheck, singleEvasion, mateThreat, &dangerous); + ext = extension(pos, move, captureOrPromotion, moveIsCheck, mateThreat, &dangerous); // Singular extension search. If all moves but one fail low on a search of (alpha-s, beta-s), // and just one fails high on (alpha, beta), then that move is singular and should be extended. @@ -1154,6 +1128,9 @@ split_point_start: // At split points actual search starts from here // Step 13. Make the move pos.do_move(move, st, ci, moveIsCheck); + if (!SpNode && !captureOrPromotion) + movesSearched[playedMoveCount++] = move; + // Step extra. pv search (only in PV nodes) // The first move in list is the expected PV if (isPvMove) @@ -1248,6 +1225,10 @@ split_point_start: // At split points actual search starts from here if (Root) { + // To avoid to exit with bestValue == -VALUE_INFINITE + if (value > bestValue) + bestValue = value; + // Finished searching the move. If StopRequest is true, the search // was aborted because the user interrupted the search or because we // ran out of time. In this case, the return value of the search cannot @@ -1275,24 +1256,16 @@ split_point_start: // At split points actual search starts from here // iteration. This information is used for time managment: When // the best move changes frequently, we allocate some more time. if (!isPvMove && MultiPV == 1) - Rml->bestMoveChanges++; - - // Inform GUI that PV has changed, in case of multi-pv UCI protocol - // requires we send all the PV lines properly sorted. - Rml->sort_multipv(moveCount); + Rml.bestMoveChanges++; - for (int j = 0; j < Min(MultiPV, (int)Rml->size()); j++) - cout << (*Rml)[j].pv_info_to_uci(pos, depth, alpha, beta, j) << endl; + Rml.sort_multipv(moveCount); - // Update alpha. In multi-pv we don't use aspiration window - if (MultiPV == 1) - { - // Raise alpha to setup proper non-pv search upper bound - if (value > alpha) - alpha = bestValue = value; - } - else // Set alpha equal to minimum score among the PV lines - alpha = bestValue = (*Rml)[Min(moveCount, MultiPV) - 1].pv_score; // FIXME why moveCount? + // Update alpha. In multi-pv we don't use aspiration window, so + // set alpha equal to minimum score among the PV lines. + if (MultiPV > 1) + alpha = Rml[Min(moveCount, MultiPV) - 1].pv_score; // FIXME why moveCount? + else if (value > alpha) + alpha = value; } // PV move or new best move } @@ -1307,7 +1280,7 @@ split_point_start: // At split points actual search starts from here && !StopRequest && !ThreadsMgr.cutoff_at_splitpoint(threadID)) ThreadsMgr.split(pos, ss, ply, &alpha, beta, &bestValue, depth, - threatMove, mateThreat, moveCount, (MovePicker*)&mp, PvNode); + threatMove, mateThreat, moveCount, &mp, PvNode); } // Step 19. Check for mate and stalemate @@ -1332,7 +1305,7 @@ split_point_start: // At split points actual search starts from here if ( bestValue >= beta && !pos.move_is_capture_or_promotion(move)) { - update_history(pos, move, depth, movesSearched, moveCount); + update_history(pos, move, depth, movesSearched, playedMoveCount); update_killers(move, ss->killers); } } @@ -1535,6 +1508,26 @@ split_point_start: // At split points actual search starts from here } + // qsearch_scoring() scores each move of a list using a qsearch() evaluation, + // it is used in RootMoveList to get an initial scoring. + void qsearch_scoring(Position& pos, MoveStack* mlist, MoveStack* last) { + + SearchStack ss[PLY_MAX_PLUS_2]; + StateInfo st; + + memset(ss, 0, 4 * sizeof(SearchStack)); + ss[0].eval = ss[0].evalMargin = VALUE_NONE; + + for (MoveStack* cur = mlist; cur != last; cur++) + { + ss[0].currentMove = cur->move; + pos.do_move(cur->move, st); + cur->score = -qsearch(pos, ss+1, -VALUE_INFINITE, VALUE_INFINITE, DEPTH_ZERO, 1); + pos.undo_move(cur->move); + } + } + + // check_is_dangerous() tests if a checking move can be pruned in qsearch(). // bestValue is updated only when returning false because in that case move // will be pruned. @@ -1695,22 +1688,19 @@ split_point_start: // At split points actual search starts from here // extended, as example because the corresponding UCI option is set to zero, // the move is marked as 'dangerous' so, at least, we avoid to prune it. template - Depth extension(const Position& pos, Move m, bool captureOrPromotion, bool moveIsCheck, - bool singleEvasion, bool mateThreat, bool* dangerous) { + Depth extension(const Position& pos, Move m, bool captureOrPromotion, + bool moveIsCheck, bool mateThreat, bool* dangerous) { assert(m != MOVE_NONE); Depth result = DEPTH_ZERO; - *dangerous = moveIsCheck | singleEvasion | mateThreat; + *dangerous = moveIsCheck | mateThreat; if (*dangerous) { if (moveIsCheck && pos.see_sign(m) >= 0) result += CheckExtension[PvNode]; - if (singleEvasion) - result += SingleEvasionExtension[PvNode]; - if (mateThreat) result += MateThreatExtension[PvNode]; } @@ -1844,8 +1834,7 @@ split_point_start: // At split points actual search starts from here assert(m != move); - if (!pos.move_is_capture_or_promotion(m)) - H.update(pos.piece_on(move_from(m)), move_to(m), -bonus); + H.update(pos.piece_on(move_from(m)), move_to(m), -bonus); } } @@ -1855,11 +1844,11 @@ split_point_start: // At split points actual search starts from here void update_killers(Move m, Move killers[]) { - if (m == killers[0]) - return; - - killers[1] = killers[0]; - killers[0] = m; + if (m != killers[0]) + { + killers[1] = killers[0]; + killers[0] = m; + } } @@ -1877,24 +1866,6 @@ split_point_start: // At split points actual search starts from here } - // init_ss_array() does a fast reset of the first entries of a SearchStack - // array and of all the excludedMove and skipNullMove entries. - - void init_ss_array(SearchStack* ss, int size) { - - for (int i = 0; i < size; i++, ss++) - { - ss->excludedMove = MOVE_NONE; - ss->skipNullMove = false; - ss->reduction = DEPTH_ZERO; - ss->sp = NULL; - - if (i < 3) - ss->killers[0] = ss->killers[1] = ss->mateKiller = MOVE_NONE; - } - } - - // value_to_uci() converts a value to a string suitable for use with the UCI // protocol specifications: // @@ -2560,7 +2531,7 @@ split_point_start: // At split points actual search starts from here // formatted according to UCI specification and eventually writes the info // to a log file. It is called at each iteration or after a new pv is found. - std::string RootMove::pv_info_to_uci(Position& pos, Depth depth, Value alpha, Value beta, int pvLine) { + std::string RootMove::pv_info_to_uci(Position& pos, int depth, Value alpha, Value beta, int pvLine) { std::stringstream s, l; Move* m = pv; @@ -2568,7 +2539,7 @@ split_point_start: // At split points actual search starts from here while (*m != MOVE_NONE) l << *m++ << " "; - s << "info depth " << depth / ONE_PLY + s << "info depth " << depth << " seldepth " << int(m - pv) << " multipv " << pvLine + 1 << " score " << value_to_uci(pv_score) @@ -2589,20 +2560,17 @@ split_point_start: // At split points actual search starts from here } - RootMoveList::RootMoveList(Position& pos, Move searchMoves[]) { + void RootMoveList::init(Position& pos, Move searchMoves[]) { - SearchStack ss[PLY_MAX_PLUS_2]; MoveStack mlist[MOVES_MAX]; - StateInfo st; Move* sm; - // Initialize search stack - init_ss_array(ss, PLY_MAX_PLUS_2); - ss[0].eval = ss[0].evalMargin = VALUE_NONE; + clear(); bestMoveChanges = 0; - // Generate all legal moves + // Generate all legal moves and score them MoveStack* last = generate(pos, mlist); + qsearch_scoring(pos, mlist, last); // Add each move to the RootMoveList's vector for (MoveStack* cur = mlist; cur != last; cur++) @@ -2614,38 +2582,13 @@ split_point_start: // At split points actual search starts from here if (searchMoves[0] && *sm != cur->move) continue; - // Find a quick score for the move and add to the list - pos.do_move(cur->move, st); - RootMove rm; - rm.pv[0] = ss[0].currentMove = cur->move; + rm.pv[0] = cur->move; rm.pv[1] = MOVE_NONE; - rm.pv_score = -qsearch(pos, ss+1, -VALUE_INFINITE, VALUE_INFINITE, DEPTH_ZERO, 1); + rm.pv_score = Value(cur->score); push_back(rm); - - pos.undo_move(cur->move); } sort(); } - // Score root moves using the standard way used in main search, the moves - // are scored according to the order in which are returned by MovePicker. - // This is the second order score that is used to compare the moves when - // the first order pv scores of both moves are equal. - - void RootMoveList::set_non_pv_scores(const Position& pos, Move ttm, SearchStack* ss) - { - Move move; - Value score = VALUE_ZERO; - MovePicker mp(pos, ttm, ONE_PLY, H, ss); - - while ((move = mp.get_next_move()) != MOVE_NONE) - for (Base::iterator it = begin(); it != end(); ++it) - if (it->pv[0] == move) - { - it->non_pv_score = score--; - break; - } - } - } // namespace